400 to 410MHz Quadrifilar Helix Antenna

Quadrifilar Helix Antenna 400-410MHz for Beidou Satellite Navigation

This product is a professional Helical Antenna in the form of a quadrifilar helix design. The antenna operates from 400MHz to 410MHz in the UHF band and is built from aluminum for good durability. As a Quadrifilar Helix Antenna, it provides left hand circular polarization which matches specific satellite downlink signals in this frequency range. The beam pattern offers hemispherical coverage with wide beamwidth, maintaining signal reception even when the antenna is installed at an angle. The antenna comes in a compact cylindrical form factor with dimensions of φ205*378mm excluding connector and bracket. It can be mounted internally or externally depending on the application requirements. The antenna features an N K type connector for secure and reliable connection.

This quadrifilar helix antenna delivers solid electrical performance across its operating range from 400MHz to 410MHz. The Voltage Standing Wave Ratio (VSWR) is rated at 1.8, which shows good impedance matching. The gain is 0dB or higher, providing sufficient signal strength for satellite signal reception. The axial ratio is 3.0dB or better, ensuring good circular polarization purity. The left hand circular polarization is specifically matched to certain Beidou and other GNSS satellite signals in the UHF band. The wide beam hemispherical pattern means the antenna can receive signals from satellites at various elevations without needing precise pointing. The construction resists high temperature, vibration, moisture, and water ingress, making it suitable for industrial and vehicle mounted installations.

One clear strength of this Quadrifilar Helix Antenna is its dedicated performance for satellite navigation in the UHF band. It is widely used for satellite signal reception and is a mainstream antenna solution in the Beidou field for lower frequency bands. The antenna is ideal for applications requiring reliable GNSS signal reception in challenging environments. The wide beamwidth allows the antenna to maintain lock on satellites even when the vehicle tilts or turns. The larger size compared to higher frequency models is typical for UHF band operation. The robust construction withstands outdoor conditions including temperature extremes, rain, and vibration. The main limitation is narrow bandwidth, as this antenna is optimized specifically for the 400-410MHz satellite band. This makes it perfect for dedicated satellite navigation applications but not suitable for ultra wideband electronic warfare or broadband communication.

In practical use, this Quadrifilar Helix Antenna handles satellite navigation reception tasks very well at UHF frequencies. For Beidou positioning systems operating in this band, it provides reliable signal reception for accurate position determination. The left hand circular polarization matches the specific satellite signals, maximizing received signal strength. For vehicle mounted and industrial installations, the antenna withstands vibration from rough roads and temperature extremes from hot sun to freezing cold. The weather resistant construction handles rain, snow, and humidity without performance degradation. The wide beam hemispherical pattern means the antenna continues receiving signals even when driving through areas with obstructed sky view. The N K connector provides a secure, weather resistant connection point suitable for outdoor use. It stands as a solid example of how a well designed Quadrifilar Helix Antenna can meet the demanding needs of Beidou and other GNSS satellite navigation applications at 400-410MHz.